Numerous types of seat post supporting devices have been designed over the years to the end of increasing riding comfort for the bicycle rider. One of the more popular approaches has been to incorporate a shock absorber into a housing which receives the seat post so as to cushion any shocks. There are occasions when it is desirable to block out the shock absorber, for example, in pedaling uphill, or in mounting or dismounting. Moreover, it is desirable to be able to adjust the height between the telescoping seat post and housing member, and it is important that the cyclist be able to control the height of the seat as well as to selectively lock the shock absorber unit in and out without having to dismount. A particular problem encountered in the telescoping seat post assemblies now in use is that of effectively locking the seat and seat post against rotation with respect to the housing and for preventing the seat post from binding when the weight or load of the rider is applied. These problems have been previously addressed and representative of the approaches which have been taken in the past is the seat support assembly set forth and described in U.S. Pat. No. 4,182,508 to C. Kallai et al wherein a latch is utilized with a protrusion on one telescoping member which will fit into an aperture on the other telescoping member to prevent relative rotation therebetween. In U.S. Pat. No. 2,467,676 to R. A. Labine a supplemental spring suspension is employed although not for the express purpose of preventing rotation of the main seat post. In U.S. Pat. No. 4,421,357 To K. Shimano, the seat frame itself is designed in such a way as to discourage relative rotation between the seat post and saddle. Other representative patents are U.S. Pat. Nos. 4,502,727 to S. A. Holcomb et al; and 2,639,760 to F. Von Szilagyi.
There continues to be a need for a telescoping seat post assembly for cycles in which the telescoping members can be effectively locked against rotation with respect to one another and nevertheless facilitate vertical adjustment and not be subject to loosening under constant jarring or vibration. In this relation, it is highly desirable that a single locking member be provided both for height adjustment of the seat and selectively locking out the shock absorber; and further wherein the telescoping members are fixed against relative rotation, irrespective of whether the shock absorber is in use, while at the same time being freely telescoping or movable without binding.